Blackfin: work around testset anomaly 05000477

Ironically, the atomic testset instruction cannot be interrupted else it
will produce incorrect results.  So disable interrupts to help it out.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 12 insertions, 2 deletions

diff --git a/arch/blackfin/mach-bf561/atomic.S b/arch/blackfin/mach-bf561/atomic.S
index 0261a5e751b..f99f174b129 100644
--- a/arch/blackfin/mach-bf561/atomic.S
+++ b/arch/blackfin/mach-bf561/atomic.S
@@ -19,6 +19,16 @@
         \reg\().h = _corelock;
 .endm
 
+.macro safe_testset addr:req, scratch:req
+#if ANOMALY_05000477
+        cli \scratch;
+        testset (\addr);
+        sti \scratch;
+#else
+        testset (\addr);
+#endif
+.endm
+
 /*
  * r0 = address of atomic data to flush and invalidate (32bit).
  *
@@ -33,7 +43,7 @@ ENTRY(_get_core_lock)
         cli r0;
         coreslot_loadaddr p0;
 .Lretry_corelock:
-        testset (p0);
+        safe_testset p0, r2;
         if cc jump .Ldone_corelock;
         SSYNC(r2);
         jump .Lretry_corelock
@@ -56,7 +66,7 @@ ENTRY(_get_core_lock_noflush)
         cli r0;
         coreslot_loadaddr p0;
 .Lretry_corelock_noflush:
-        testset (p0);
+        safe_testset p0, r2;
         if cc jump .Ldone_corelock_noflush;
         SSYNC(r2);
         jump .Lretry_corelock_noflush